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Regenerative suspension dampers


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#1 Magoo

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Posted 01 September 2013 - 19:56

This is worthy of discussion, I think. Complete unedited press release below: 

 

 

 

 

ZF and Levant Power Develop the World's First Fully Active, Regenerative Suspension for Automobiles

- ZF Friedrichshafen AG has entered into partnership with Levant Power Corp. to build the world's first fully active suspension system with energy recovery function

- GenShock-technology is a fully active system for passenger cars which combines dynamics, safety and comfort characteristics with minimum energy consumption

- Intelligent, simple design creates the basis for future cost-effective volume production

Automakers have long sought a suspension that allows sport cars handling while maintaining the comfort of a premium luxury sedan. The difficulty in achieving this outcome rests in balancing comfort and handling; comfort requires a soft suspension to absorb bumps, while handling requires stiffness for control. Previous attempts to achieve high-bandwidth active suspension have fallen short due to cost, complexity and power consumption. ZF and Levant Power are now developing GenShock-technology to unite the vast gains of active suspension with modest power consumption, minimal complexity and affordable cost.

The recently agreed cooperation between ZF Friedrichshafen AG and Levant Power Corp., based in Woburn, Mass., U.S., paves the way for revolutionary damper technology. "We look forward to working closely together with Levant Power. The objective is to develop the world's first fully active and regenerative suspension, make it ready for volume production and introduce it to the market. Thus, we are promoting efficient innovations that are tailored to meet global requirements," said Rolf Heinz Rüger, in charge of the Suspension Technology business unit of ZF's Car Chassis Technology division.

"Ride and handling are at the core of the driving experience. With GenShock-technology, ZF and Levant will reinvent that experience," continued Shakeel Avadhany, Founder & CEO of Levant Power.

Newly conceived valve

An innovative functional unit, fitted to the outside of the ZF damper, forms the technological basis of the active, regenerative system. The valve technology has been developed specifically for this application. The very compact unit is composed of its own control unit, an electric motor and an electrohydraulic gear pump. Driven by an electronically controlled electric motor, the gear pump regulates the oil flow in the damper. "For dynamics, comfort and safety, it is essential that active forces can be applied into the chassis," explained Rüger. For this reason, the damping characteristic curve not only adapts optimally and automatically to each driving situation, but bodywork pitch motions are also virtually eliminated during abrupt braking maneuvers and rolling motions. Moreover, the technology is capable of actively raising each individual wheel.

Electricity for the vehicle power supply

As soon as the driving situation permits, the innovative valve system automatically uses the swaying motion of the damper piston to recover energy. Then, the system guides the oil in the damper in such a way that it drives the electric pump motor. This then functions like a generator; it converts the generated kinetic energy into electricity and feeds it into the vehicle power supply, thus contributing to a reduction in CO2 emissions. This effect is most powerful when the vehicle is traveling on poor quality country roads.

With this project, ZF is making use of its long-standing know-how of adaptive dampers. Continuous Damping Control (CDC) has been winning over vehicle manufacturers since its market launch in 1994 and is still doing so with its fourth generation. The production numbers continue to rise; 2011 marked the temporary record high with more than 2.2 million dampers produced for the following customers: Alpina, Audi, Bentley, BMW, Ferrari, Maserati, Opel, Rolls-Royce, Mercedes-Benz, Porsche and Volkswagen. A total of around 14 million CDC systems have already come off the production line at ZF, and the company expects an annual production of more than three million CDC units for passenger car applications alone by 2016. In addition, there are ZF systems for buses, trucks, agricultural machines and motorcycles.

About:

ZF is a global leader in driveline and chassis technology with 121 production companies in 26 countries. In 2012, the Group achieved a sales figure of about EUR 17.4 billion with approximately 75,000 employees. In order to continue to be successful with innovative products, ZF annually invests about five percent of its sales (2012: EUR 861 million) in research and development. ZF is one of the 10 largest automotive suppliers worldwide.

Levant Power Corp. is an emerging technology company headquartered in Woburn, Massachusetts working to develop the world's first fully active, regenerative suspension for the automotive, trucking, mass transit, and defense industries. The company holds several patents focused primarily on vehicle dynamics, and is the originator of GenShock and Activalve technology. Levant Power was founded in 2009 out of the Massachusetts Institute of Technology.



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#2 Greg Locock

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Posted 01 September 2013 - 20:20

Interesting. I'm surprised its ZF rather than Bosch.



#3 Fondles

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Posted 01 September 2013 - 22:51

Is it going to generate much useful power though?
AFAIK the damper rates on a smooth-ish road are in the order of inches per second and only over a short distance as well.

Look at an alternator: they have a small diameter but have to spin pretty quickly to produce useful power.

 

Just curious ....



#4 Magoo

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Posted 01 September 2013 - 22:59

I guess it depends how you look at it. Thousands of pounds are being pitched and thrown around constantly, albeit a very short distance at a time.

 

The other day I was reminded of the old differential cooler systems used in the early days of NASCAR. The differential lube was pumped through a heat exchanger by an extra rear shock. 



#5 desmo

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Posted 02 September 2013 - 01:53

Stop your car while out driving.  Stoop down and touch a damper to feel how hot it is.  That's how much power is potentially available this way.



#6 Fondles

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Posted 02 September 2013 - 02:46

Stop your car while out driving.  Stoop down and touch a damper to feel how hot it is.  That's how much power is potentially available this way.

 

 

So not much at all then?



#7 Greg Locock

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Posted 02 September 2013 - 05:45

I have the data for the power converted to heat by a shock, but not til I get back to work next week. I must admit I'm not expecting a huge amount, and of course it'll be zero on a chassis dyno so the manufacturers won't be all that interested. 



#8 Lee Nicolle

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Posted 02 September 2013 - 08:12

To get a shock hot you have to be driving quite spiritedly.On race cars damping quite stiff springs they get very hot quickly.
Or very rough roads will do it too.
Having played Speedway over the years feeling the heat in the shocks is always interesting. When I used road car shocks with steel bodys they got very hot, Using a proper alloy big body race shock means they just get luke warm. Reputedly they also use better oil too.
Though a Sprintcar shock on a rough track still gets quite warm. Though sedan ones get hotter a they work harder with stiffer springs. More work= more heat.

As a total aside oils are not all oils. I used to use normal 80/90 in the diff and after even a hard 10 laps it was quite warm. Several of us went to using special or synthetic oils and a lot of the heat went away. The old Halibrand quick changes using Ford V8 gears were a true case of that. And they are not breaking pinions anymore either

#9 RDV

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Posted 02 September 2013 - 12:09

Did some work with them on Dakar cars, off road damping at high speeds (..up to 9m/s) and long strokes can supply a lot of energy. On tracing cars value not so high due to limited travel, but still useable...every bit helps.



#10 Magoo

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Posted 02 September 2013 - 13:08

More hybrid news -- GM CEO says don't be surprised to see a C7 Corvette hybrid... 

 

 

 

http://www.latimes.c...0,3899803.story



#11 Magoo

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Posted 02 September 2013 - 15:53

Stop your car while out driving.  Stoop down and touch a damper to feel how hot it is.  That's how much power is potentially available this way.

 

About like an alternator then, I suppose. 



#12 Keith Young

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Posted 02 September 2013 - 17:15

See post #6

 

http://www.f1technic...php?f=6&t=15395



#13 Magoo

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Posted 02 September 2013 - 18:06

I love how they talk about 200W like it's nothing. It's more than this vehicle's entire electrical system. 

 

 

kdry.jpg
 


#14 Greg Locock

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Posted 02 September 2013 - 20:24

Yup 200W on the dyno would be worth chasing. 200W in real driving would be hidden in the signal to noise ratio. Does driving with your headlamps on increase your fuel consumption? yes, obviously. Can you measure that?



#15 Fondles

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Posted 02 September 2013 - 20:58

Yup 200W on the dyno would be worth chasing. 200W in real driving would be hidden in the signal to noise ratio. Does driving with your headlamps on increase your fuel consumption? yes, obviously. Can you measure that?

 

 

I'm sorry but I'm still a bit pessimistic about this. You have to have an alternator of some sort being driven by the engine (on a road car at least) and having it make 200W is, as mentioned, a very easy task. 

So if you can get 200W out of the suspension system, is it worth adding all that weight & complexity when you already have a device that does that?

I can see how for an off-road machine it could be a good thing though.



#16 Magoo

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Posted 03 September 2013 - 01:30

Yup 200W on the dyno would be worth chasing. 200W in real driving would be hidden in the signal to noise ratio. Does driving with your headlamps on increase your fuel consumption? yes, obviously. Can you measure that?

 

This is where we are going. The Nissan Leaf uses 20 kWh of battery capacity. 



#17 Greg Locock

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Posted 03 September 2013 - 03:31

Fair enough, yes for EVs it might be more beneficial. But then EVs probably spend less time on rough roads, so the gains might be smaller.



#18 Lee Nicolle

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Posted 03 September 2013 - 10:54

I'm sorry but I'm still a bit pessimistic about this. You have to have an alternator of some sort being driven by the engine (on a road car at least) and having it make 200W is, as mentioned, a very easy task. 
So if you can get 200W out of the suspension system, is it worth adding all that weight & complexity when you already have a device that does that?
I can see how for an off-road machine it could be a good thing though.

Is it? Most modern alternators on common cars are usually 80 amp. occasionally 100. Which are bigger and draw more power. Though with all the often unecesary bling and bobs on modern cars they are needed.
Though the Caddy above had a lot of bling. electric seats and top, A/C, lots of courtesy lights over 50 years ago with probably a 35 amp generator. Most GM cars world wide did not grow alternators before about 64. Then 35 amp.

#19 mariner

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Posted 05 September 2013 - 00:04

I had not realised what a significant share of the damper market is held by ZF.

 

Nonetheless I think Greg has hit on the main probelm - if it doesn't help on the roller dyno - based CO2/fuel economy figures why would a mfr. pay to put it on the car?



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#20 Canuck

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Posted 05 September 2013 - 08:14

If they're really capable of 200 watts, that on the order of >17% of an 80 amp system. I don't know what that might mean in total fuel consumption as I've no idea what the alternator costs to run. 17% isn't negligible though 17% of 0 is one supposes.

#21 Magoo

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Posted 05 September 2013 - 10:36

If they're really capable of 200 watts, that on the order of >17% of an 80 amp system. I don't know what that might mean in total fuel consumption as I've no idea what the alternator costs to run. 17% isn't negligible though 17% of 0 is one supposes.

 

 

80A is a pretty small alternator these days. Mr. Locock makes a good point that on a 450 hp sedan, 200 watts is diddly squat.

 

On the other hand: on a Chevy Volt where there is a grand total of 11 kWh of energy available to propel the vehicle before the gasoline engine is forced to kick on, 200 watts is considerable. 

 

By the way, I am not claiming or denying 200W for regen damping. That's just a number someone threw out there. 



#22 Powersteer

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Posted 07 September 2013 - 09:26

put a rack with two one way pinions on each side connected to a motor and viola! one way pinions each, one for load motion and one for rebound so that the motor spins in one direction only so that overgearing wont be a problem when load chages. energy generative suspension load controllers. sensors on the rack to tell the motor if its going up or down.



#23 Ray Bell

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Posted 11 September 2013 - 21:52

I'm worried about the suggestion that other things are too complex...

 

And this isn't?